Yang Jianfen is listed as an inventor on the patent 'Preparation Method For Sodium-Based Modified Phenolic Resin Hard Carbon Negative Electrode.' Based on the technical field and content of the patent, Yang Jianfen's research is focused on the development of advanced anode materials for sodium-ion batteries, particularly on the synthesis and modification of phenolic resin-derived hard carbon electrodes. Further personal or professional details about affiliations or academic background are not available from the given patent citation.